Female black flies have razor-sharp mandibles, and they are often responsible for cutting into the skin of mammals and birds. These flies live in the flowing water of streams, and they measure between five and fifteen millimeters long. Although they are not harmful to humans, a large number of black flies in a field can be quite a nuisance, particularly to livestock.
Most people recognize mosquitoes as the most common blood-feeding insects. These insects are members of the Culicidae family. They feed on organic matter that exists in standing water. Female mosquitoes are attracted to heat, carbon dioxide, and lactic acid. Once a female flies lands on the host’s skin, she injects a tube into the flesh, where she can lay her eggs. She then releases saliva, which prevents the blood from clotting.
Insect blood is not red, and is often yellow or green. It contains proteins and hormones, but does not contain hemoglobin. However, it is important to note that some insects have red blood. This is because their eyes contain red pigment, which makes them appear red. If you notice flies in your home that have red blood, you should check your bedding or floor for stains.
Insects are often very picky about which animals they feed on. For example, blind, flightless flies may prefer to feed on bats. Their skin microbiomes may be the reason why they prefer certain hosts over others.